Ours if 5 gallons but since we mainly use it to do the dishes and very
rarely use it for showers, that's all we need. If you're not actively
cruising where there aren't showers, why bother? Doesn't your marina have
showers?

"Joe" wrote in message
om...
How large do you think your water heater
should be?

I have a 5 gallon but I think I must double the effort.

Joe